Thursday, June 25, 2009

Denial of Service Attacks for Dummies

Last night, I was so outraged by a report on the NY Times blog about the Iranian government posting photos of demonstrators and asking visitors to identify them. A quick perusal of the page with Google Persian Translator I'm usually a fanatical fan of free speech, but the idea of a government using the web to pick on nonviolent demonstrators was too much for me. We may not be able to do anything about the government sicing basiji on the protesters, but we can certainly do something when they try to get them with the web. The outrage prompted me to google some means of shutting the site down. (Caveat: Cyberwar guide reminds us to only attack sites recommended by trusted sources. I felt this qualified because it was mentioned in the Times, and because I researched the page myself.)

The simplest kind of site attack is a Denial of Service attack. This works by sending so many requests to a site's server that it shuts down. Every time you connect to a site, you send a request, so the best way to send a lot of requests to a site is to reload it over and over. If you can open a browser and hit reload, you can help.

An even better way, however, is to have your computer automatically reload the page for you. You can leave this it running for hours on end. In the case of the protest-busting site above, I opened 20 browser tabs, set them to reload every 5 seconds, and left them on overnight. When I woke up in the morning, the site was down.

Here's how to do it:1. Open firefox. If you don't have firefox, you can download it here.2. Download the "Reload Every" tool from the Mozilla site. Install it and restart Firefox.3. Go to the site you want to attack.4. Right click on the site's homepage. Mouse over "reload every" and select "5 seconds"4.5. (Or, if you want to be really devious) Right click on the site's homepage, mouse over "reload every" and select "custom". It will ask you to specify an amount of time for it to keep reloading. Set it to 1 second.6. Leave it running for as long as you like. If you're feeling especially subversive, open multiple browser tabs and repeat the above instructions.